Slab



H. H. BUNKER Dec. 28, 1937.

SLAB

Filed June 2e, 193e fNHIMm Patented Dec. 28, 1937 UNVIEDv STATES fpAre-NT oFFicE Y Y Y `SLAB t Herbert'n Bnkenfjersey city, N. J. Application `.time 26, 1936, semi No. svn-45 f4 claims. (ci. 72-71) This invention relates to slabs for roadways and the like, and particularly to metallic framework or skeletons which maybe used' as part of a concrete-filled slab or as an open slab. Among 5 Vthe objects of the invention is to provide a metallic skeleton structure which can be built in its entirety Vfrom common bars and shapes, and which is rigid and relatively light in Weight for thelo'adcarrying strength it possesses. "l

Another object oi the invention is to provide a metallic skeleton having built-up longitudinal beam members'with each beam member having a webconsisting of'a bent bar providing alternate bends and diagonal struts, and in which the beam members of the skeleton are so arranged that the diagonal struts in r'every other beam member lies in the same plane cross-wise of the skeleton so that the diagonal struts in adjacent beams lie in planes inclined to each other.

Y o Another object of the invention is to provide a metallic skeleton having longitudinally-extending `beams or truss members which are spacedfrom each other by a set of bars with each bar individually engaging the upper chords of the beams, and another set of bars with each bar individually engaging the lower chords of the beams. j Further and other objects of the present invention will be hereinafter set forth in` the accompanying specification and claims and demon- 30 strated by the drawing which shows by way of illustration a preferred embodiment andthe principle of my invention, and what I'now consider the best mode in which I have contemplatedapplying that principle. Other embodimentsofthe 3 3 invention employing the same principle `maybe used and structural changes made as 'desired by those skilled in the art within the spirit ofthe appendedr claims without departing `from 'the present invention. k 40 In the drawing, Fig. 1 .isa plan of a steel' skeleton employing the principles of my invention and showing, for illustrative purposes, portions broken away and a portion having a lling of cementitious material. 45 Fig. 2 is a section o-n line 2-2 of Fig. 1. Fig. 3 is a section online 3-3 of Fig. 2. Fig. 4 is a perspective view showing particularly the manner of joining members entering into the` construction of the metallic skeleton, some of the 50 members being shown as detached for illustrative purposes.

The longitudinal beams or truss members consist of parallel bars I0, II, which form the upper and lower chord members of the beams. They 55 are connected together by bent bars I2. 'I'he bent bars I2 have the outside of their loops I3, I4, welded or otherwise attached to the upper and 21o-wer bars I0 and II, respectively, so that each Vpair or" Vupper and lower bars lII) and II and associated'bent bar I2 constitutes a single beam or truss member. All the longitudinal beams inf a y. given metallic skeleton 'are similar to each other, but they are so cut vand arranged that the diagonal portions 15 of adjacent longitudinal beams lie in intersecting planes extending across 10 thelongitudinal beamsand cross-wise. of the slab.`

4This results in the staggered appearance illustrated in Fig. A2, whether or not al1 of the beams within a single skeleton unit end in a straight line Vassembled in parallel rows and are secured to.-

gether by two sets of cross-bars I6 and I1 which engage the upper and lower chords of the longitudinal beams, respectively. Each cross-bar is provided with notches I8 land I9 (Fig. 3) which alternate in respect to each other along the bar and are so shaped as to engage the chords of the longitudinal beams. In the present case, the longitudinal bars which form the upper and lower chords of the beams are rectangular in kcross-section so the notch I8 is rectangular and has a depth and width commensurate with the depth and width of the longitudinal bar I0. The notch I9 is also dimensioned to engage the bar I0, but it has an additional cut-out portion 20 to accommodate the loop I3of the bent bar I2. The lower cross-bars I1 are similarly notched and suitably dimensioned for engaging the lower longitudinal bars II and the loops I4 of the bent bars I2. vl preferably weld the cross-bars I6, l1, to the members they are associated with so as to enable distribution of stresses crosswise of the skeleton and also provide rigid bracing transverse of the slab.

' Additional locking of the longitudinal bars, cross-bars and bent bars is obtained by vertical strut members 22 which extend between the' upper and lower chords of each longitudinal beam where the loops are located in the bent bars I4, but for certain purposes the vertical struts may be omitted if desired. Every other vertical strut has one end abutting the under side 23 of a bend I3 of the bent bar, and its other end 24 abutting the inside surface of the opposite longitudinal bar so that each vertical strut acts as a stress member in conjunction with the two adjacent diagonal truss members I2. In order that the ends of a vertical strut may abut against the bent bar I4 and longitudinal bar as just explained, each end must be notched as at 25, 26, to accommodate the cross-bars. Each vertical strut is preferably welded to its associated members at its upper and lower ends.

It will be understood from the nature of the construction that all of the vertical strut members are similarly shaped, but that their upper and lower ends are reversed in respect to each other for adjacent strut members along any one longitudinal beam. This is clearly shown in Fig. 4, wherein the upper end of the right-hand vertical strut engages the under side of the bend I3 in the bent bar ifi, and the lower end of the lefthand vertical strut engages the inside of the lower bend I4 of the same bent bar, and these two ends of the struts are similarly notched. The other ends of the same struts are similarlyv but more deeply notched because of their abuts tion to obtain greater tensile strength than is necessary for the upper bar l0, but thecrosssectional dimensions of these two bars may be the same, as would preferably be the case'if the metallic skeleton were to be used as an open slab without any lling. This is merely a matter of selecting the sections which will provide the strength and position of the neutral axis desired. When lling is employed, a form must be provided for supporting the filling when it is poured, and this form may constitute a temporary mold or a permanent metallic plate 3U secured to the under sides of the lower bars of the .longitudinal beams. The skeleton is then in condition to support a concrete lling 3|.

I wish it to Ybe understood that the metallic skeleton of my invention may be used for either a lled slab or an open slab, and that when used as a filled slab the nature of the filling material is unimportant except insofar as it may affect 3 the sizes and shapes of the various bars entering into the construction.

What I claim is:

l. A metallic skeleton for a slab comprising longitudinally-extending trussbeams and cross-bars, each truss beam having upper and lower chord members in the form of upper and lower bars and a bent bar in between the upper and lower bars with reverse loops at the ends of straight portions forming diagonal truss members, said bent bar being continuous for several loops and having the outside portions of the loops engaging the upper and lower bars, and vertical strut members each having an end abutting the inside of a loop in the bent bar and an end abutting the inside surface of the longitudinal chord member opposite the engaged loop so as to serve as a brace between the upper and lower chords of a truss beam, the alternate vertical strut members being arranged in inverted. relation in reference to the intermediate vertical strut members so that all of the upper and lower loops of the bent bai' are engaged by the vertical strut members.

2. A metallic skeleton for a slab comprising longitudinally-extending truss beams and crossbars, each truss beam having upper and lower chord members in the form of upper and lower bars, and a bent bar in between the upper and lower bars of each truss` beam, said bent bar having loops engaging the upper and lower bars and portions intermediate the loops extending opposite loops in the bent bars, each strut being notched at one end for enabling vertical engagement with a cross-bar and a bent bar and at its other end with a cross-bar and longitudinal bar of a chord member so as to serve as a brace between the upper and lower chords of a truss beam.

3. A metallic skeleton for a slab comprising longitudinally-extending truss beams having chords and open webs, said truss beams being arranged parallel to one another and separated from one another by a set of upper cross-bars and a set of lower cross-bars, the cross-bars being arranged in pairs with one cross-bar above the other,.the upper cross-bars being notched for engaging the upper chords of the longitudinal truss beams and the lower cross-bars being notched for engaging the lower chords of the longitudinal truss beams, each truss beam having a bent bar in between the upper and lower chords and providing truss members constituting diagonal portions extending from the intersections of the upper cross-bars with the upper chord of the longitudinal truss beam to the intersections of the lower cross-bars with the lower chord of the longitudinal truss beam.

4. A metallic skeleton for a slab comprising longitudinally-extending truss beams arranged parallel to one another and having upper and lower chords separated by an open web, a set of cross-bars for spacing the upper chords of said truss beams and a set of cross-bars for spacing the lower chords of said truss beams, said crossbars being provided with notches for engaging the upper and lower chords, the webfor each of said truss beams comprising a bent bar having a series of loops in engagement with the upper and lower chords with successive loops passing through and engaged by a notch in an upper cross-bar and then by a notch in a lower crossbar at the intersections of the respective crossbars with the upper and lower chords of a truss beam.

HERBERT H. BUNKER. 

